The present disclosure relates to a terminal apparatus, a communication control apparatus, a wireless communication system, and a communication control method.
In a cellular communication system, frequency division duplex (FDD) refers to a mechanism for dividing an uplink signal and a downlink signal by a frequency. For example, in a Long Term Evolution (LTE) scheme, which is a new communication scheme following a 3G mobile communication scheme, FDD is used, except for in a time division (TD)-LTE scheme. Table 1 shows a list of frequency channels (bands) for the LTE standardized by 3GPP (Third Generation Partnership Project) which is described in “3GPP TS 36.101 v10.0.0.”
TABLE 1E-UTRAOperat-Du-ingUplink (UL) bandsDownlink (DL) bandsplexBandFUL—Low-FUL—HighFDL—Low-FDL—HighMode 11920 MHz-1980 MHz2110 MHz-2170 MHzFDD 21850 MHz-1910 MHz1930 MHz-1990 MHzFDD 31710 MHz-1785 MHz1805 MHz-1880 MHzFDD 41710 MHz-1755 MHz2110 MHz-2155 MHzFDD 5824 MHz-849 MHz869 MHz-894 MHzFDD 6830 MHz-840 MHz875 MHz-885 MHzFDD 72500 MHz-2570 MHz2620 MHz-2690 MHzFDD 8880 MHz-915 MHz925 MHz-960 MHzFDD 91749.9 MHz-1784.9 MHz1844.9 MHz-1879.9 MHzFDD101710 MHz-1770 MHz2110 MHz-2170 MHzFDD111427.9 MHz-1447.9 MHz1475.9 MHz-1495.9 MHzFDD12698 MHz-716 MHz728 MHz-746 MHzFDD13777 MHz-787 MHz746 MHz-756 MHzFDD14788 MHz-798 MHz758 MHz-768 MHzFDD15ReservedReservedFDD16ReservedReservedFDD17704 MHz-716 MHz734 MHz-746 MHzFDD18815 MHz-830 MHz860 MHz-875 MHzFDD19830 MHz-845 MHz875 MHz-890 MHzFDD20832 MHz-862 MHz791 MHz-821 MHzFDD211447.9 MHz-1462.9 MHz1495.9 MHz-1510.9 MHzFDD.. .... .... ..331900 MHz-1920 MHz1900 MHz-1920 MHzTDD342010 MHz-2025 MHz2010 MHz-2025 MHzTDD351850 MHz-1910 MHz1850 MHz-1910 MHzTDD361930 MHz-1990 MHz1930 MHz-1990 MHzTDD371910 MHz-1930 MHz1910 MHz-1930 MHzTDD382570 MHz-2620 MHz2570 MHz-2620 MHzTDD391880 MHz-1920 MHz1880 MHz-1920 MHzTDD402300 MHz-2400 MHz2300 MHz-2400 MHzTDD412496 MHz-2690 MHz2496 MHz-2690 MHzTDD
Referring to Table 1, uplink (UL) frequencies of a band 7 are defined as 2500 MHz to 2570 MHz and downlink (DL) frequencies are defined as 2620 MHz to 2690 MHz and a frequency interval between the UL and DL is 120 MHz. Also, uplink (UL) frequencies of a band 5 are defined as 824 MHz to 849 MHz and downlink (DL) frequencies are defined as 869 MHz to 894 MHz and a frequency interval between the UL and DL is 45 MHz.
In the FDD, uplink transmission and downlink transmission can be performed at the same time. Meanwhile, in time division duplex (TDD), the uplink transmission and the downlink transmission are performed at different time slots. For example, in a wireless local area network (LAN) scheme such as IEEE802.11a/b/g/n, TDD is mainly adopted. When an industry-science-medical (ISM) band is used as a frequency channel of the wireless LAN, an uplink signal and a downlink signal are transmitted according to a time division scheme, in an ISM band of 2400 MHz to 2500 MHz.
In recent years, in such situations, the case in which a cellular communication system and other kinds of wireless communication systems such as the wireless LAN are used at the same time at places adjacent to each other is increasing. For example, some latest mobile routers support an Internet access function in the LTE scheme and provide high-speed Internet access through the LTE to a terminal apparatus connected by the wireless LAN scheme. In addition, there is the case in which a femtocell base station (small base station that is introduced to cover an area smaller than a macrocell) put to practical use in many countries supports a wireless LAN connection function.